WO2000033301A1 - Systeme integre de suivi optique pour support magnetique - Google Patents

Systeme integre de suivi optique pour support magnetique Download PDF

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Publication number
WO2000033301A1
WO2000033301A1 PCT/US1999/028350 US9928350W WO0033301A1 WO 2000033301 A1 WO2000033301 A1 WO 2000033301A1 US 9928350 W US9928350 W US 9928350W WO 0033301 A1 WO0033301 A1 WO 0033301A1
Authority
WO
WIPO (PCT)
Prior art keywords
array
optical
magnetic
light source
servo system
Prior art date
Application number
PCT/US1999/028350
Other languages
English (en)
Inventor
Archibald W. Smith
Original Assignee
Storage Technology Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Storage Technology Corporation filed Critical Storage Technology Corporation
Publication of WO2000033301A1 publication Critical patent/WO2000033301A1/fr

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Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B21/00—Head arrangements not specific to the method of recording or reproducing
    • G11B21/02—Driving or moving of heads
    • G11B21/08—Track changing or selecting during transducing operation
    • G11B21/081—Access to indexed tracks or parts of continuous track
    • G11B21/086—Access to indexed tracks or parts of continuous track on tapes
    • G11B21/088—Access to indexed tracks or parts of continuous track on tapes with track following of accessed part
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/54—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head into or out of its operative position or across tracks
    • G11B5/55—Track change, selection or acquisition by displacement of the head
    • G11B5/5504—Track change, selection or acquisition by displacement of the head across tape tracks
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/54—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head into or out of its operative position or across tracks
    • G11B5/55—Track change, selection or acquisition by displacement of the head
    • G11B5/5521—Track change, selection or acquisition by displacement of the head across disk tracks
    • G11B5/5526—Control therefor; circuits, track configurations or relative disposition of servo-information transducers and servo-information tracks for control thereof
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/58—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B5/584—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on tapes
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/58—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B5/596—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on disks

Definitions

  • the present invention relates to the field of servo tracking systems which integrate an optical head array into a magnetic head to follow optical servo tracks disposed on the magnetic side of a medium.
  • Modern magnetic tape drives employ combination read/write heads that incorporate multiple side-by-side data heads along with one or more read heads dedicated to sensing servo tracks added to, or interleaved with the data tracks.
  • the accuracy of the servo system must increase to maintain proper alignment. If the size of the servo tracks is not decreased, then valuable surface area on the tape is not available for data storage, and the head becomes more complicated due to the unequal spacing of the magnetic heads. Reducing the size of the servo tracks frees more space on the tape, but makes it more difficult for the servo system to maintain the necessary positional accuracy.
  • Dedicated servo tracks can be eliminated all together using a complex process of encoding the track and data together when writing, and signal processing to extract a position error signal when reading. Even when this is done, differences in the format of the servo information from tape drive type to tape drive type can make a tape written on one machine unreadable on another.
  • optical servo tracks were placed on the back side of the tape. While this improved tracking accuracy, this method is difficult to carry out in small form factors because access is required on both sides to the tape. Further more, establishing initial mechanical alignment from tape drive to tape drive, and maintaining that alignment for several years is difficult with the optical tracking components on one side of the tape and the magnetic data components on the other side. To overcome this alignment problem, optical marks have been added to the magnetic head to calibrate the optical tracking components. This however increases the size and complexity of the total system.
  • the present invention provides an improved servo tracking system that uses an optical head array integrated with multi-unit magnetic heads to follow optical servo tracks defined on the same side of the media as the magnetic layer.
  • the base system is a combination head, having multiple magnetic heads to read and write data in a magnetic layer on a medium.
  • the improvement is the integration of an optical head array into the combination head, and the incorporation of optical servo tracks on the magnetic layer side of the medium.
  • the optical head array includes a light source array that illuminates the optical servo tracks through a beam splitter array and a lens array. Light incident on the optical servo tracks is reflected back through the lens array and beam splitter array to a bi-cell photo detector array.
  • the bi-cell photo detector signals are amplified by a differential amplifier array to produce error signals that are indicative of the alignment of the head with the optical tracks.
  • the error signals are combined by a circuit to produce a position error signal.
  • FIG. l is a block diagram of one optical head and an optical servo track according to the invention.
  • FIG. 2 is a fragmentary cut away view of a medium, and a combination head showing a magnetic head and one optical head;
  • FIG. 3 is a fragmentary cut away view of a medium and an array of optical heads
  • FIG. 4 is an elevated view, as seen looking through a tape medium, at a combination head with a multi-unit read magnetic head, a multi-unit write magnetic heads, and four optical heads;
  • FIG. 5 is an elevated view, as seen looking through a disk medium, at a combination head with multiple magnetic heads and three optical heads;
  • FIG. 6 is a fragmentary cut away of an alternate embodiment of FIG. 2 using holographic elements, one substrate for the light source array, and another substrate for the sensor array;
  • FIG. 7 is a fragmentary cut away of an alternate embodiment of FIG. 2 using binary optics and a single substrate for the light source array and the sensor array;
  • FIG. 8 is a drawing of one bi-cell photo detector with a graph of the optical servo track image intensity versus position aligned above the drawing, and a graph of the error signal versus position aligned above that;
  • FIG. 9 is a fragmentary profile drawing of a medium in which embossed depressions define the optical servo tracks.
  • FIG. 10 is a fragmentary profile drawing of a medium using a layer of amorphous to crystalline phase change material to define the optical servo tracks.
  • FIG. 1 shows one set of the optics and electronics that comprise an optical head 18 according to the present invention.
  • Each optical head 18 has a light source 22 that emits an incident light beam 24.
  • the incident light beam 24 is deflected by a beam splitter 26 through a lens 28 and onto an optical servo track 30 provided on the magnetic medium.
  • the optical servo track 30 reflects the light beam 24 back through the lens 28 toward the beam splitter 26.
  • Beam splitter 26 allows some of the reflected light beam 32 to pass straight through to where it impinges on a bi-cell photo detector 34.
  • Each cell of the bi-cell photo detector 34 produces a photo current on electrical leads 36 and 38 proportional to the amount of the reflected light beam 32 received by that cell.
  • a differential amplifier 40 outputs an error signal on lead 42a proportional to the difference between the photo currents on electrical leads 36 and 38.
  • the optical head 18 described above is repeated multiple times to produce an array of error signals on leads 42a-42n.
  • Circuit 44 processes these error signals on leads 42a-42n to produce a position error signal on lead 20 for use by a servo mechanism.
  • FIG. 2 shows the physical form of a medium 46 and an optical head 18.
  • the optical servo track 30 is disposed on the magnetic layer 48 on the same side of the substrate 50. Alternatively, the optical servo track 30 is placed between the magnetic layer 48 and substrate 50. All of the optical head 18 optics and electronics are bonded to a multi-unit magnetic head 52 to form a stable integrated combination head 54.
  • the light source 22 is an array of infrared light emitting diodes (LED), operating at a wavelength of approximately 0.8 ⁇ m.
  • the LEDs may be fabricated on a GaAs substrate 56.
  • the light source 22 can be any other light emitting device, coherent or non coherent, solid state, or the like which can be fabricated small enough to be integrated with a magnetic head, and of sufficient low power to avoid thermal problems.
  • Other operating wavelength can be selected based upon the accuracy requirements, the choice of optical material for beam splitter 26 and lens 28, and the choice of the bi-cell photo detector 34 material.
  • the parameters of lens 28 are selected based upon the optical resolution required to achieve the desired positioning accuracy.
  • the optical resolution is determined by the numerical aperture of the lens 28, which is approximately the ratio of the radius of the lens to the focal length.
  • a numerical aperture of approximately 0.5 has a resolution of about one wavelength - which is 0.8 ⁇ m for the infrared light emitted by the light source 22.
  • This numerical aperture, and an approximately one millimeter spacing between the lens 26 and the medium 46, illustrated as distance 58, requires a lens diameter of approximately one millimeter, illustrated as distance 60.
  • the reflected light beam 32 reaching the bi-cell photo detector 34 is of low power. Therefore, it is desirable that the bi-cell photo detector 34 and the differential amplifier 40 be physically placed as close together as possible to avoid picking up stray noise. This is achieved in the preferred embodiment by fabricating the bi-cell photo detector 34 as positive-intrinsic-negative silicon photo diodes in the same silicon substrate 62 as the differential amplifier 40.
  • the preferred embodiment of the beam splitter 26 is a half-silvered or dielectric coated mirror that deflects the incident light beam 24 at a right angle. Other embodiments for the beam splitter will be discussed later.
  • FIG. 3 shows a fragmented view containing several optical heads 18a-18n.
  • the number of optical heads 18a-18n and their center-to-center spacing 64 can be tailored to meet the needs of various applications. Increasing the number of optical heads 18a-18n increases the position accuracy and reliability of the servo tracking system. Reducing the center-to-center spacing 64 between optical heads 18a-18n decreases the size of the combination head 54. In the preferred embodiment, the center-to-center spacing 64 between optical heads 18a-18n is approximately two millimeters.
  • the arrays of components are fabricated as monolithic units. Lenses 28a-28n are fabricated using injection molding to create a single lens array unit 66.
  • the beam splitter 26 is fabricated by injection molding as a single piece.
  • LED light sources 22a-22n are fabricated on a common GaAs substrate 56.
  • the bi-cell photo detectors 34a-34n and differential amplifiers 40a-40n are fabricated on a common silicon substrate 62.
  • the circuit 44 can also be fabricated on the silicon substrate 62.
  • FIG. 4 shows the preferred embodiment of the system as seen looking at the combination head 54 through a tape medium 46.
  • the combination head 54 comprises a multi-unit read magnetic head 52a, and a multi-unit write magnetic head 52b, with the multiple optical heads 18 sandwiched there between.
  • the medium 46 is a magnetic tape with a plurality of optical servo tracks 30a-30g. As shown in the figure, the number of optical servo tracks 30a-30g exceeds the number of lenses 28a- 28d. In this situation, the combination head 54 is stepped between optical servo track 30a-30g to reach the entire width of the tape medium 46. For other applications, the number of optical heads 18 matches the number of optical servo tracks 30 and the combination head 54 covers the entire width of the medium 46.
  • FIG. 1 shows the preferred embodiment of the system as seen looking at the combination head 54 through a tape medium 46.
  • the combination head 54 comprises a multi-unit read magnetic head 52a, and a multi-unit write magnetic head 52b, with the multiple optical heads 18 sandwiche
  • combination head 54 comprises one multi-unit magnetic head 52 bonded to the optical heads 18.
  • the medium 46 is a magnetic disk with a plurality of concentric optical servo track 30a-30e.
  • FIG. 6 is an alternative embodiment of the present invention.
  • the half-silver or dielectric coated mirror of the beam splitter 26 is replaced by a holographic element or a binary optical element
  • These types of beam splitters 26 allow the light source 22 and bi- cell photo detector 34 to be coplanar. Mounting the GaAs substrate 56 and the silicon substrate 62 side-by-side makes for easier assembly of the optical head 18 since the incident light beam 24 and reflected light beam 32 are focused in the same plane.
  • FIG. 7 is another alternative embodiment.
  • the light source 22 and bi-cell photo detector 34 can be fabricated on the same silicon substrate 62.
  • other semiconductor materials such as GaAs, GaAlAs, and other III-V and II- VI compounds can be used to form the light source 22 and bi-cell photo detector 34 on a common substrate.
  • FIG. 8 is a top view of a bi-cell photo detector 34 with a graph of the intensity of the optical servo track image 74 produced by the focused reflected light beam 32, and the subsequent error signal 92 imposed above.
  • the bi-cell photo detector 34 consists of a first cell 68 and a second cell 70 separated by a gap 72.
  • the gap 72 is oriented transverse to the optical servo track 30.
  • a zero volt error signal 92 is produced.
  • the amplitude of the error signal 92 is proportional to displacement, while the polarity is determined by the direction of displacement.
  • FIG. 9 is one embodiment of the medium 46 showing two of the optical servo tracks 30a-30b.
  • a polymer layer 76 between the substrate 50 and magnetic layer 48 is embossed with the pattern for the optical servo tracks 30a-30b. Embossing may be accomplished with a formatting roller or like process.
  • the embossed depth, illustrated as depth 78, should be approximately l/6th of the wavelength of the light emitted by light source 22. For a GaAs LED which emits light at a wavelength of 0.8 ⁇ m, the embossed depth is 80 nm. Such a shallow embossed depth is benign to the recording process. Alternatively, the magnetic recording can be restricted to the space between the embossed tracks.
  • a reflective layer 80 is applied over the entire surface of the magnetic layer 48.
  • An example of a reflective layer 80 is an aluminum layer with a thickness of about 30 nm, illustrated as distance 82. This aluminum layer is sufficiently thin to be benign to the recording process.
  • the width of the optical servo tracks 30a-30b, indicated as distance 84, is typically 2 ⁇ m to 7 ⁇ m but can take other values to optimize the position error signal.
  • a layer of lubricant 86 may be applied over the reflective layer 80.
  • FIG. 10 is another embodiment of the medium 46.
  • the magnetic layer 48 is flat against the substrate 50.
  • the amorphous to crystalline phase change layer is sufficiently thin so as not to disrupt the recording process.
  • the optical servo tracks 30a-30b are reflective crystallized lines in the amorphous to crystalline phase change layer 88 with a typical width of 2 ⁇ m to 7 ⁇ m, indicated by distance 84.
  • a lubricant 86 or other protective layer covers the amorphous to crystalline phase change layer 88.
  • the amorphous to crystalline phase change layer 88 may alternatively be disposed between the magnetic layer 48 and substrate 50.
  • the writing of the optical servo tracks 30a-30b, and the subsequent reading is performed at the wavelength at which the magnetic layer 48 is transparent.

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  • Moving Of The Head To Find And Align With The Track (AREA)
  • Optical Recording Or Reproduction (AREA)

Abstract

La présente invention concerne un modèle évolué de système de bras de têtes comportant d'une part une matrice de têtes optiques intégrées à la tête magnétique et d'autre part des pistes d'asservissement optiques incorporées à la face magnétique d'un support. Les matrices de têtes optiques comportent une matrice de sources lumineuses qui éclairent individuellement les pistes d'asservissement optiques via une matrice de séparateurs de faisceaux et une matrice de lentilles. Les faisceaux lumineux touchant les pistes d'asservissement optiques sont renvoyés via la matrice de lentilles et la matrice de séparateurs de faisceaux vers photodétecteurs bicellulaires. Les signaux provenant du photodétecteur bicellulaire sont amplifiés chacun par un amplificateur différentiel de façon à donner des signaux d'erreur caractéristiques de l'alignement de la tête magnétique par rapport aux pistes d'asservissement optiques. La combinaison de ces signaux d'erreur par un circuit donne un signal d'erreur de position.
PCT/US1999/028350 1998-12-02 1999-11-30 Systeme integre de suivi optique pour support magnetique WO2000033301A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US09/203,784 1998-12-02
US09/203,784 US6275349B1 (en) 1998-12-02 1998-12-02 Integrated optical tracking system for magnetic media

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WO2000033301A1 true WO2000033301A1 (fr) 2000-06-08

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6856484B2 (en) 2001-09-05 2005-02-15 Quantum Corporation Magnetic servo of a recording head
EP1677305A3 (fr) * 2004-12-28 2009-02-18 Quantum Corporation Alignement de focalisation optique sur bande magnétique de stockage de donnée

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19913382C2 (de) * 1998-03-24 2002-08-14 Quantum Corp Mehrkanaliges Magnetbandsystem mit einem optischen Spur-Servo
US6771450B1 (en) * 1999-02-17 2004-08-03 Quantum Corporation Method of writing servo signal on magnetic tape
US6961200B2 (en) * 1999-07-27 2005-11-01 Quantum Corporation Optical servo track identification on tape storage media
US7082006B1 (en) * 1999-08-10 2006-07-25 Storage Technology Corporation Compact optical tracking system for magnetic tape
WO2001065556A1 (fr) * 2000-03-02 2001-09-07 Matsushita Electric Industrial Co., Ltd. Dispositif d'enregistrement magnetique
US6940681B2 (en) * 2001-08-20 2005-09-06 Quantum Corporation Optical to magnetic alignment in magnetic tape system
US7187515B2 (en) * 2003-02-05 2007-03-06 Quantum Corporation Method and system for tracking magnetic media with embedded optical servo tracks
US6980390B2 (en) * 2003-02-05 2005-12-27 Quantum Corporation Magnetic media with embedded optical servo tracks
US7116514B2 (en) * 2003-10-20 2006-10-03 Quantum Corporation Methods and systems for magnetic recording
US7149050B2 (en) * 2003-10-20 2006-12-12 Quantum Corporation Diffractive position sensors and control systems
US7139152B2 (en) * 2003-10-20 2006-11-21 Quantum Corporation Servo methods and systems using existing data structures and optical masks
US7136255B2 (en) * 2003-10-20 2006-11-14 Quantum Corporation Servo methods and systems using masked medium edge position sensors
US7085095B2 (en) * 2003-10-20 2006-08-01 Quantum Corporation Electromagnetic void-sensing probes and position control systems
US7102845B2 (en) * 2003-10-20 2006-09-05 Quantum Corporation Servo methods and systems using existing data structures and medium edge position
JP2007519163A (ja) * 2004-01-21 2007-07-12 マイクロコンティニュアム・インコーポレーテッド 事前フォーマット済み線状光データ記憶媒体
US7369483B2 (en) * 2004-01-21 2008-05-06 Microcontinuum, Inc. Pre-formatted linear optical data storage medium
US7184233B2 (en) * 2004-06-04 2007-02-27 Quantum Corporation Dual source tracking servo systems and associated methods
US20060103968A1 (en) * 2004-11-12 2006-05-18 Jurneke Joe K Dynamic skew compensation systems and associated methods
US7499235B2 (en) * 2005-03-18 2009-03-03 Quantum Corporation Auto-servo tape system and associated recording head
US7826169B2 (en) * 2007-04-25 2010-11-02 Quantum Corporation Servo error detection and compensation utilizing virtual data tracking servo methods

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0344759A2 (fr) * 1988-06-03 1989-12-06 Insite Peripherals, Inc. Milieu à grande densité de pistes avec pistes optiques d'asservissement; méthode et appareil d'inscription des pistes sur le milieu
US5493553A (en) * 1992-12-22 1996-02-20 Thomson Csf Method and apparatus for preventing cross-talk during reproduction of data recorded on a high density recording medium
US5796710A (en) * 1992-12-22 1998-08-18 Thomson-Csf Information recording medium encoded to enable track following and method of recording
EP0877372A2 (fr) * 1997-05-09 1998-11-11 Hewlett-Packard Company Système de positionnement de tête avec photocapteur
WO1999028909A1 (fr) * 1997-12-01 1999-06-10 Storage Technology Corporation Systeme asservi optique pour dispositif d'entrainement de bande

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3426337A (en) * 1964-12-21 1969-02-04 Ibm Positioning system for random access device
US4057833A (en) 1974-10-03 1977-11-08 U.S. Philips Corporation Centering detection system for an apparatus for playing optically readable record carriers
FR2514913B1 (fr) * 1981-10-16 1986-07-04 Bull Sa Dispositif opto-electronique de lecture d'informations contenues sur un support magnetique
US4633451A (en) * 1982-06-30 1986-12-30 International Business Machines Corporation Optical servo for magnetic disks
FR2539883B1 (fr) * 1983-01-25 1987-11-06 Bull Sa Dispositif optique de focalisation pour la lecture d'un support d'informations defilant devant lui
US4615944A (en) * 1983-05-17 1986-10-07 Minnesota Mining And Manufacturing Company Amorphous magneto optical recording medium
US4558383A (en) 1983-06-30 1985-12-10 International Business Machines Corporation Information storage disk transducer position control system using a prerecorded servo pattern requiring no alignment with the storage disk
FR2597643A1 (fr) * 1985-11-08 1987-10-23 Seiko Epson Corp Systeme de lecture de signal magneto-optique
US4864552A (en) * 1986-08-29 1989-09-05 Laser Magnetic Storage International Company Driving signal for coarse servo employing sampled offset signal
JPH0739063Y2 (ja) * 1987-03-13 1995-09-06 グローリー工業株式会社 磁気及び光センサ
US4843494A (en) * 1987-10-15 1989-06-27 Polaroid Corporation Data storage apparatus using optical servo tracks
US4987505A (en) * 1987-10-19 1991-01-22 Victor Company Of Japan, Ltd. Magnetic head device having photo detector cell
US4958245A (en) 1988-04-07 1990-09-18 Insite Peripherals, Inc. Apparatus and method for optical servo control with media having information storage and servo control regions of different reflectivities
US5563868A (en) * 1990-06-18 1996-10-08 Matsushita-Kotobuki Electronics Industries, Ltd. Optical servo system for magnetic disk
JP3166181B2 (ja) * 1991-02-28 2001-05-14 株式会社日立製作所 磁気記憶装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0344759A2 (fr) * 1988-06-03 1989-12-06 Insite Peripherals, Inc. Milieu à grande densité de pistes avec pistes optiques d'asservissement; méthode et appareil d'inscription des pistes sur le milieu
US5493553A (en) * 1992-12-22 1996-02-20 Thomson Csf Method and apparatus for preventing cross-talk during reproduction of data recorded on a high density recording medium
US5796710A (en) * 1992-12-22 1998-08-18 Thomson-Csf Information recording medium encoded to enable track following and method of recording
EP0877372A2 (fr) * 1997-05-09 1998-11-11 Hewlett-Packard Company Système de positionnement de tête avec photocapteur
WO1999028909A1 (fr) * 1997-12-01 1999-06-10 Storage Technology Corporation Systeme asservi optique pour dispositif d'entrainement de bande

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6856484B2 (en) 2001-09-05 2005-02-15 Quantum Corporation Magnetic servo of a recording head
EP1677305A3 (fr) * 2004-12-28 2009-02-18 Quantum Corporation Alignement de focalisation optique sur bande magnétique de stockage de donnée

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US6563662B2 (en) 2003-05-13
US20010043426A1 (en) 2001-11-22
US6275349B1 (en) 2001-08-14

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